Eric is soon thrust into an experimental army unit known as the Bolt Eaters. Thrown into the latest cesspools of war and conflict across the world, the Bolt Eaters make short work of any opponents. It's almost a cakewalk for the high-tech robots.

When aliens decide to invade, stranding his unit in the middle of nowhere, Eric is forced to face the ultimate test with the machines he has come to know as brothers: a deadly game of cat and mouse played against a technologically superior, utterly alien foe - a game whose stakes include not just their lives, but the lives of every man, woman, and child on the planet.